First, a structure of a data recording/reproducing apparatus according to a conventional technique will be described with reference to FIG. 19. FIG. 19 is a structure diagram of a data recording/reproducing apparatus according to a conventional technique.
An interface circuit 10 is a portion which supplies digital AV signals, instructions and responses to and receives the digital AV signals, the instructions and the responses from digital AV equipment 80.
A system controller 20 is a device which presides over and controls each means which forms the data recording/reproducing apparatus, controlling so that a digital AV signal which is supplied through the interface circuit 10 or an encoder circuit 40 is recorded on a disk 31 and such that the digital AV signal recorded on the disk 31 is outputted through the interface circuit 10 or a decoder circuit 41. Meanwhile, the system controller 20 controls such that the digital AV signal which is recorded on the disk 31 is saved and deleted in the unit of files.
A buffer control circuit 21 is a circuit which outputs the digital AV signal, which is supplied through the interface circuit 10 or the encoder circuit 40, to recording/reproducing means 30 after temporarily storing the digital AV signal in a buffer RAM 22, and outputs the digital AV signal to the interface circuit 10 or the decoder circuit 41 after temporarily storing the digital AV signal supplied from the recording/reproducing means 30 in the buffer RAM 22, to thereby ensure continues recording or continuous reproduction of the AV signal.
The buffer RAM 22 is a device which has a function as a register to read out temporarily saved data in accordance with a necessity.
The recording/reproducing means 30 is means of recording the digital AV signal received from the buffer control circuit 21 on the disk 31, and reproducing the digital AV signal recorded on the disk 31 and outputting to the buffer control circuit 21.
The encoder circuit 40 is a circuit which encodes an inputted analog AV signal. The decoder circuit 41 is a circuit which decodes the digital AV signal outputted by the recording/reproducing means 30 and supplies the analog AV signal to a reproducing apparatus (not shown) to thereby reproduce images and sounds.
File management means 260 is means of referring to and updating free area management information, recording file management information, deletion file selecting criteria information and the like to thereby manage reproduction, saving, deletion, etc., of files, issuing an instruction to the system controller 20 so that an entered digital AV signal is recorded on the disk 31 in the unit of files and the digital AV signal recorded on the disk 31 is reproduced in the unit of files. Further, the file management means 260 issues an instruction to the system controller 20 so that the digital AV signal recorded on the disk 31 is deleted in the unit of files. The free area management information, the recording file management information, and the deletion file selecting criteria information will be described later.
Deletion file selecting criteria information setting means 261 is means which is for a user to set up the deletion file selecting criteria information which is for selecting a file which is to be deleted as new data are written (hereinafter referred to as “delete candidate”). A deletion file selecting criteria herein described in relation to the conventional technique is the number of viewing and the recording time.
The digital AV equipment 80 is equipment which supplies the digital AV signal, an instruction and a response to and receives the digital AV signal, the command and the response from the interface circuit 10 of the data recording/reproducing apparatus.
Operations of the data recording/reproducing apparatus according to the conventional technique having such a structure will be described with reference to FIG. 19.
In response to a user's instruction, the deletion file selecting criteria information setting means 261 provides the file management means 260 with the deletion file selecting criteria information which is for selecting a file which is to be deleted as new data are written. As herein described, the deletion file selecting criteria information setting means 261 notifies the file management means 260 of such setup which requires to first delete a file which bears the number of viewing of 1 or more and the earliest recording start time.
Next, a description will be given on an operation of the data recording/reproducing apparatus according to the conventional technique as the digital AV equipment 80 receives data as a signal. The data referred to here are data to be saved on the disk 31 as a file FID1 whose size is 4 GB.
The digital AV equipment 80 outputs to the data recording/reproducing apparatus this data to be recorded and the volume of this data to be recorded, as a signal. The system controller 20 analyzes the signal which is supplied through the digital AV equipment 80, and notifies the file management means 260 that this data are data which are to be saved as a 4 GB file.
The file management means 260 determines to save the data supplied through the digital AV equipment 80 as a signal on the disk 31 as the file FID1, and instructs the system controller 20 to execute this.
Receiving the instruction which was outputted as a signal from the file management means 260, the system controller 20 writes the data supplied through the digital AV equipment 80 on the disk 31 as the file FID1, and notifies the file management means 260 of this.
The data recording/reproducing apparatus according to the conventional technique writes data in a manner described above. An operation for writing is similar to the writing operation already described earlier, when a free capacity in the disk 31 is larger than the size of data which are to be newly written.
The data recording/reproducing apparatus according to the conventional technique keeps writing data on the disk 31 which is loaded in the recording/reproducing means 30 in this manner, so that the files FID1, FID2, FID3, . . . FID999 are saved on the disk 31. The recording/reproducing means 30 in some cases outputs data saved as a file on the disk 31 through the decoder circuit 41, in response to an instruction from a user (so that the user views the data saved as a file on the disk 31). Further, as described in detail later, the number of outputting is described as the number of viewing in the recording file management information.
The file management means 260 holds the free area management information and the recording file management information. The free area management information contains a recording capacity, a recorded capacity and a free capacity, whereas the recording file management information contains recording area information, the recording start time, a file size and the number of viewing, both of which are as shown in FIG. 20. FIG. 20 shows charts of the free area management information and the recording file management information updated according to the conventional technique.
Next, a description will be given on operations of the data recording/reproducing apparatus according to the conventional technique as the digital AV equipment 80 receives new data as a signal. The new data are data to be saved on the disk 31 as a file FID1000 whose size is 5 GB.
The digital AV equipment 80 outputs to the data recording/reproducing apparatus this new data which are to be recorded and the volume of this data to be recorded, as a signal. The system controller 20 analyzes the signal supplied from the digital AV equipment 80, and notifies the file management means 260 that this data are data which are to be saved as a 5 GB file.
The file management means 260 refers to the free area management information which is shown in FIG. 20, and recognizes that a free capacity in the disk 31 is 2 GB which is smaller than the size of the file (5 GB) which is to be newly saved.
The file management means 260 recognizes that the file FID1 which bears the number of viewing of 1 or larger and the oldest recording time is a delete candidate, determines to delete the file FID1 and ensure a free area of 6 GB in total so that the data received as the signal through the digital AV equipment 80 will be written on the disk 31 as the file FID1000, and issues an instruction to delete FID1 to the system controller 20.
Receiving the instruction outputted as the signal from the file management means 260, the system controller 20 deletes FID1 and writes the data newly supplied through the digital AV equipment 80 on the disk 31 as the file FID1000. The system controller 20 notifies the file management means 260 of this.
Upon receipt of the notification from the system controller 20, the file management means 260 updates the free area management information and the recording file management information which are shown in FIG. 20 respectively into such free area management information and recording file management information as those shown in FIG. 21. FIG. 21 shows charts of the free area management information and the recording file management information updated in the conventional technique.
By the way, the recent years have seen development of a disk device mounting an HDD (Hard Disk Drive). Recording capacities and data transfer speeds of data recording/reproducing apparatuses are accordingly rapidly improving. This has led to easy realization of recording and reproduction of a plurality types of data, such as video data, audio data and still image data, using only one data recording/reproducing apparatus.
However, since management in a disk according to conventional techniques is effective in only one recording area, it has been heretofore impossible to manage files by data type.